The Convection And Moisture EXperiment (CAMEX) is a series of field research investigations sponsored by the Earth Science Enterprise of the National Aeronautics and Space Administration (NASA). The fourth field campaign in the CAMEX series (CAMEX-4) was held in 16 August - 24 September, 2001 and was based out of Jacksonville Naval Air Station, Florida.

CAMEX-4 is focused on the study of tropical cyclone (hurricane) development, tracking, intensification, and landfalling impacts using NASA-funded aircraft and surface remote sensing instrumentation. The High Altitude MMIC Sounding Radiometer (HAMSR) microwave instrument was was mounted in a wing pod of a NASA ER-2 research aircraft, which operates at an altitude of 65,000 feet and therefore can overfly hurricanes. HAMSR participated in a number of sorties during CAMEX-4, and a large amount of data was collected.

HAMSR operated with 25 spectral channels in the 50-190 HGz region, and it provided measurements that can be used to infer the 3-D distribution of temperature, water vapor, and liquid water in the atmosphere, even in the presence of clouds. The primary derived measurements are vertical profiles of temperature, water vapor and liquid water, from the surface to 100 mb in 2-4 km layers.

During this campagin, HAMSR and other instruments were able to observe the following storms (all in the Atlantic region):